From c7150963b7db0123299f2430eea956c6a83f69d4 Mon Sep 17 00:00:00 2001

From: Gerd Hoffmann <kraxel@redhat.com>

Date: Tue, 4 Jun 2019 05:12:46 +0100

Subject: [PATCH 4/8] usb-host: avoid libusb_set_configuration calls

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RH-Author: Gerd Hoffmann <kraxel@redhat.com>

Message-id: <20190604051246.11374-5-kraxel@redhat.com>

Patchwork-id: 88472

O-Subject: [RHEL-8.1.0 qemu-kvm PATCH 4/4] usb-host: avoid libusb_set_configuration calls

Bugzilla: 1713677

RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>

RH-Acked-by: Max Reitz <mreitz@redhat.com>

Seems some devices become confused when we call

libusb_set_configuration().  So before calling the function check

whenever the device has multiple configurations in the first place, and

in case it hasn't (which is the case for the majority of devices) simply

skip the call as it will have no effect anyway.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Message-id: 20190522094702.17619-4-kraxel@redhat.com

(cherry picked from commit bfe44898848614cfcb3a269bc965afbe1f0f331c)

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 hw/usb/host-libusb.c | 18 ++++++++++--------

 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c

index dd3ed02..587ff70 100644

--- a/hw/usb/host-libusb.c

+++ b/hw/usb/host-libusb.c

@@ -1220,19 +1220,21 @@ static void usb_host_set_address(USBHostDevice *s, int addr)

 static void usb_host_set_config(USBHostDevice *s, int config, USBPacket *p)

 {

-    int rc;

+    int rc = 0;

     trace_usb_host_set_config(s->bus_num, s->addr, config);

     usb_host_release_interfaces(s);

-    rc = libusb_set_configuration(s->dh, config);

-    if (rc != 0) {

-        usb_host_libusb_error("libusb_set_configuration", rc);

-        p->status = USB_RET_STALL;

-        if (rc == LIBUSB_ERROR_NO_DEVICE) {

-            usb_host_nodev(s);

+    if (s->ddesc.bNumConfigurations != 1) {

+        rc = libusb_set_configuration(s->dh, config);

+        if (rc != 0) {

+            usb_host_libusb_error("libusb_set_configuration", rc);

+            p->status = USB_RET_STALL;

+            if (rc == LIBUSB_ERROR_NO_DEVICE) {

+                usb_host_nodev(s);

+            }

+            return;

         }

-        return;

     }

     p->status = usb_host_claim_interfaces(s, config);

     if (p->status != USB_RET_SUCCESS) {

-- 

1.8.3.1